Safety appliance for bias-cutting machines



Aug. 13, 1929. WETMQRE SAFETY APPLIANCE FOR BIAS CUTTING MACHINES Filed July 18, 1928 2 Sheets-Sheet 1 3 M 6 2 t M .J 6 W 0 0 a M 7 Mm 7 5 3 w o 9 HI I IDL 6 6 I J 14 mm A wa m A 7 6 m 7 7 n 0 v m H 9 w r w 0 m m 2 o O 0 n 5 6 0 T8% 6 H 8 u A M II. n n 1% m w w T 1 FY (a m m J W l A 9 no H 0 6 \L 7 F I\ Fl'll I 0 W a /9 9 v m m 3 n T M m 9 n a 8 mm m n W F m E l Laurence Weimore Aug. 13, 1929. L. WETMORE SAFETY APPLIANCE FOR BIAS CUTTING MACHINES Filed July 18, 1928 2 Sheets-Sheet 2 ya w W m Patented Aug. l3, 1929.

- A l E T F F I C E LAUBJENCE ETMORE, OF ALAMEDA, CALIFORNIA, ASSIGNOB, TO THE GOODYEAR TIRE dz RUBBER CQIVIPANY, OF AKRQN, UHIO, A COR-PURATQON OF OHIO.

SAFETY APPLIANCE FOR BIAS-CUTTING MACHINEE.

Application filed. July 18,

This invention relates to machines for cutting fabric into strips, and it has particiiilar relation to machines of the above designated character having safety devices which shall be especially applicable for protecting the machine operators from injury when removing the strips of fabric.

An object of the invention is to provide a safety device capable of operating synchro- .nously with the reciprocating knife and fabric clan'iping bar of a machine, for preventing an operator from disposing his hands within the path of movement of the knife and bar.

In the manufacture of pneumatic tire casings andother similar articles composed partially of rubberized fabric, it common practie first to cut the fabric into strips with the cords therein disposed diagonally to the edges of the strips. A machine employed generally in performing this operation is known as a bias cutting machine and. comprises principally, a. reciprocating knife or cutting mechanism, a reciprocating clamping bar for clamping the fabric in the path of the cutting mechanism during the operative movement thereof, and means for feeding fabric periodically between the clamping bar and the cutting mechanism. Subsequently to the operation of the cutting mechanism, the clamping bar is moved to an inoperative position, and a biased cut strip is removed manually from the machine by operators. If the operators did not remove the strips synchronously with. the operation of the machine, their hands would be engaged and probably seriously injured by the clamping bar or the knife during their operation. Such injuries were not uncommon in the operation of these machines.

This invention obviates the dangers heretofore referred to, by the provision. of a safety device which prevents the hands of an operator from being engaged by the clamping bar or the knife duringtheir operative movement. Th e illustrated embodiment of the invention comprises a plurality of resilient guards pivoted to the frame of the machine adjacent. the clau'iping edge of the clauming bar, which are operable synchronously with the reciprocating movements thereof. When the bar inoperatively dis- 1928. Serial No. 293,556.

posed, the guards effectively prevent an operator from placinp his hands between the bar and the machine frame, while subsequently, during the operation thereof, the guard is disposed closely adjacent the bar. in order that an operator may remove a sev ered strip of fabric from the machine.

For a better uiiulerstanding of the invention, reference may now be had to the ac- COHILMUIylIlQ drawings, forming a part of the s] 3e ci.licatiou, of which;

l igure 1 is an elevational view of a bias cutting machine employing a safety device constructed according to the invention;

Figure 2 is a cross-sectional View on a larger scale taken substantially along the line II H of Figure l;

lligure 3 is a detailed plan view of a portion of the machine. one larger scale, illustrating the relative position of one of the guards Figure 4; is a cross-svztional view, on a larger scale, taken substantially alongthe line lfV-lV of l igure 1, showing the position of the guard when the clamping bar and knife are in their inoperative positions; and

Figure 5 is a detail view showing the mechanism for causing the cutting knife to assume operative and inoperative positions.

A, frame 7, employed in practicing the invei'ition, comprisrsa horizrmtally disposed base plate 8 having; a vertically disposed pair of elongate members 9 rigidly secured to opposite ends thereof, a horizontally disposed truss 1O connecting intermediate portions of the eli'mgate members 9, and a vertically disposed elongate member 11 interposed between intermediate portions of the truss 10 and the base plate 8. A motor 12, rigidly secured on the base plate 8 adjacent the elongate member 11, is provided with a driving shaft 13 having a pinion 14L rigidly secured at one end thereof which meshes with a larger gear 15 rigidly secured upon one end. of a horizontally disposed counter shaft 16. A pinion l7, rigidly secured upon the opposite end of the counter-shaft, meshes with a large gear 19 which, in turn, is rigidly secured upon the end of a shaft 20 disposed above the base plate in parallel relation to the counter-shaft 16. The shaft 2 and the iii counter-shaft 16 are journaled severally in bearings 18 rigidly secured in spaced relation upon the upper surface of the base plate 8.

' As best shown by Figure 2, a pin 21 projecting from one side of the gear 19, pivotally supports a connecting rod 22, which at its upper end is pivoted to a crosshead 25, slidably mounted in a. guide 26 secured rigidly upon the member 11. The cross-bead has secured thereto, a bar 27 provided at its upper end with rack teeth 28 disposed in intermeshing relation to a pinion 29 rotatably mounted on a stud shaft 30, which is secured in an opening formed in the truss 10.

The pinion 29 is secured rigidly to a grooved pulley 31 over which is trained a pair of convolutions of a cable 32. Portions of the cable 32 extending oppositely from the pulley 31 are trained over pulleys 34 and 35 which are rotatably mounted adjacent the ends of an obliquely disposed raceway 36 that is adjustably secured to the truss 10. The ends of the cable are secured to the opposite ends of a bar 33, which is slidably mounted upon a spaced pair of bolts etl) and 41 projecting from a block 37 through elongate slots 38 and 39, respectively. The block 37 is slidably disposed (Figure at) between suitable guide surfaces formed within the raceway 36. The block also is provided with a knife 42, slidable at right angles to the plate 33, and which, at its inner end, has a pin 43 that proj ects into a diagonally extend ing slot 1 1 in the bar.

From this description, it is apparent that when the motor 15 is energized, the block 37 is reciprocated within the raceway 3G by the oppositely directed movements of the cable 32. At the beginning of each of the aforesaid movements of the cable 32, the bar 33 is moved relative to the block 37 a distance equal to the length of the slots 38, 39, thus moving the pin 13 and the knife 42 laterally with respect to the bar into either a retracted or a projected position. In its projected position, as shown by Figure 5, the knife 42 extends through a slot as in the raceway, whereas in its alternative position, as shown by Figure 4, the knife is retracted from the slot.

An endless cam slot 47, formed at one side of the gear 19, operatively engages a cam follower 48, which is pivoted at 1-9 to the member 11 of the frame 7. The opposite ends of a connecting rod 52 are pivoted respectively upon a stud 50, projecting from the follower 48, and a toggle 53, an end 5st of which is pivotally connected to a collar 55 secured to the stud shaft 30, while the opposite end 56 is pivotally connected to a collar 57 secured upon a bar 58 slidably sup ported in an opening formed axially of the stud'shaft. The opposite end of the bar 58 is provided with rack teeth 59, which mesh with a segmental gear 60, keyed to a shaft 61 rotatably supported in bearings ()2 mounted upon the raceway 36. A pair of crank arms 63, connected to the shaft (31 at opposite ends thereof, are pivotally connected by a pair of links Gil: to a clamping bar (35, which is slidably mounted bctwccn a spaced pair of guides (37 secured to the raceway 3(3. The inner edge of the clamping bar cm is provided with a groove (38, which registers with the slot formed in the raceway 30, when the bar is in its operative position.

A. sheet of fabric (39 is fed periodically between the inner edge of the clamping bar and the raceway 36 from a roll 70, which is rotatably supported between the upper cnds of the members i), by a gear and ratchet clutch mechanism '71. One end of a couuccting rod 72 is connected opcralivcly to the gears of the mechanism 71, while the opposite end thereof is connected to a crank arm 73 secured at one end of the shaft 20. \Vbcn the fabric has been moved a predetermined distance between the clamping bar ()5 and raceway 36, the former is urged against the latter and a narrow strip is severed from the sheet of fabric by the reciprocation of the knife 42.

The outer edge of the clamping bar of; is provided with a bracket 75, having a cylindrical member 76 pivoted thereto, as indicated at 77. A rod 78 is slidably mounted in one end of the cylindrical member and is resiliently connected thereto by a spring 79 that is secured at its opposite ends, as indicated at 80 and 82, to the members 7( and 78, respectively. A slot 83 in the member 76 provides a guide for the connection 82 and permits relative movement between the mcm bers 7G and 78. The free end of the rod 78 is pivotally connected at 85 to a crank arm 86 keyed to a shaft 87, which is rotatably supported in bearings 88 secured to the guides 67. An elongate guard plate 90, comprising a straight portion 91. and an angled outer portion 92, is secured at one edge to a spaced pair of brackets 93, which arc secured rigidly to the shaft 87 adjacent the opposite ends thereof.

hen, during the operative movement of the knife 4-2, the clamping bar (35 is disposed against the raceway 36, as shown by l igure 2, and the guard plate 90 is disposed immediately adjacent the clamping edge of the bar, there is no possibility of injury to an operators hands, because they could not be inserted between the clamping bar and the raceway. At the termination of the culling movement of the knife 4-2, when the clamping bar is released, the severed strip of fabric is renioved by the operator before the guard 90 is moved away from the clamping bar. This is possible by reason of the resilient connection between the bar and guard which permits the latter to lag behind the ill) movement ofthe former. The guard thereafter moves into the position illustrated by Figure l, thus retaining the operators hands a safe distance from the clamping bar and the raceway until after the latter are again brought into'operatim position as hereinbefore describral.

In machines of type, ordinarily two operators are employed removing the strips of fabric, one grasping the strip adjacent each end thereof. For this reason, preferably two of the guards are employed, one adjacent each end of the raceway. However, it is to be understoml that the number of guards may be vaa'ied, or that a singl e guard of considerable length. may be employed.

From the foregoing description, it is apparent that a safety device of the type doseribed positively prevents an operator from moving' his hand. to a position between the clamping bar and the raccuay of the machine. lt also apparent that since the guard member operates in synchronism with. the clan'iping bar, it is disposed in such posh tion. at the end of the strip cutting operation that an operator is enabled to grasp narrow strips of fabric and remove the same. Moreover, because of the resilient connection botween the guard member and the clamping bar, the latter is .maintaimal in proximity to the clamping bar until. such strip of fabric is removed. In addition, the safety device enables an operator to focus his attention entirely upon the task of removing the strips .in syncln-ouism with the operation of the machine.

Although .l have ill striated only one form which the invention may assume and have described in detail only a single application thereof, it will be app-art-mt to those skilled in the art that the invention is not so limited, but that various minor modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

What- I claim is:

1. In an apparatus of the class described, a frame for supporting a sheet of fabric, a cutting mechanism movably molnitcd. upon the frame, clamping means for seciu'ing the fabric in operative relation to the cutting mechanism, and a guard for preventing the lurnds of an operator. from being inserted between the clamping); means and the frame.

2. In an apparatus of the class described, a frame for supporting; a sheet of fabric, a cuttii'ig mechanism movably mounted upon the frame, clamping mea s for securing the fabric in operative relation to the cutting nieclnmism, and a movable guard for prcventing; the hands of an operator from bc inp' ins -rted between the clamping means and the frame.

In an apparatus of the class described,

a frame for supporting a sheet of fabric, a cutting mechanism movably mounted upon the fral'ne, clan'ipinp; means for securing); the fabric in operative relation to the cutting mechanism, and a movable guard operati vcly connected to the clamping means, for preventing; the hands of an operator from be ing inserted. between the damping means and the frame.

4t. in an apparatus of the class described, a frame for supporting a sheet of fabric, a cutting mechanism. movably mounted upon the frame, clampiruz; means for securing); the fabric in operative relation to the cutting mechanism. and a mr uzbln ,rruard o ieratively connected to the clamping;' means, for preventing the hands of an 0].)t-51'tll101 from being; inserted between the clamping means and the frame. said operative connection in cluding a resilient means.

5. in an apparatus of the class desu-rihed, a frame for supporting a sheet of fabric, a cutting mechanism movably mounted upon the frame, clamping means for securing the fabric in operatim relation to the cutting mechanism, and a guard operatively connected to the clamping); means, said connection including telescopic members resiliently connected.

6. In an apparatus of the class described, a frame for supporting a sheet of fabric, a cutting; meclnrnism movably mounted on the frame, clamping means for securing the fabric in operative relation to the cutting mechanism, and a guard pivoted on the frame and resiliently connected. to the clamp innmeans.

7. In an apparats of the class described, a frame for supporting a sheet of fabric, a cuttin mechanism movably mounted on the frame, reciprocable clamping means for securing the fabric in operative relation to the cutting mechanism, and a guard pivoted on. the frame and resiliently CUHllt-Etilltd to the clamping means.

8. In an apparatus of the class described, a frame for sup 'iorting a sheet of fabric, a cutting mechanism movably mounted on the frame and having a cyclic movement, and being, operable during only a portion of the cycle, clamping means operable in synchronism with the cutting mechanism for clamping the fabric in operative relation to the frame, and a guard movably mounted on the frame and also opt-mating in synchro nism with the cutting mechanism, said guard. when the cutting operation is completed, being juxtaposed relative to the path of said cutting operation, whereby a strip of fabric of small width may be rcmowd.

9. In. an apparatus of the class described, a frame forsupporting a sheet of fabric, a cuttin muchanismv movably mounted on the frame, a clamping bar for securing the fabrie in operative relation to the cutting, In witness whereofllhave hereunto signed 10 mechanism, and a guard movably mounted my name.

on the frame and operating in synchronism Signed at Alameda, in the county of Ala- With the cutting mechanism, said guard bemeda, State of California, this 12th day of ing juxtaposed relative to the clamping J uly, 1928. means when the latter is in operative position, and substantially spaced therefrom LAURENCE \VETMORE. When the clamping means is in inoperative position. 

